"They are among the first people from a space habitat, the 'Ark', to return to Earth after a devastating nuclear apocalypse.

"In the sixth season, after 125 years in 'cryosleep', 'Clarke', 'Bellamy' and the others wake up to find out that they are no longer orbiting Earth and have been brought to a new habitable world, 'Alpha', also known as 'Sanctum'.

"After landing on this world, they discover a new society, led by ruling families known as the 'Primes'. However, they also discover new dangers in this new world, and a mysterious rebel group, known as the 'Children of Gabriel'. Now the inhabitants try to find a way to live together in peace..."